If your YouTube video is blocked or removed then the best possible reason could be copyright infringement.
Copyright owners such as musicians, songwriters, composers, who create new music for the record labels and artists, etc; can decide whether to permit you to use their music in your videos. Some owners may directly decide to block or remove the video immediately after they come to know about it.
You might have used songs or music without giving credits or acknowledging the audio you used for your dance videos. Please address or announce in the description the creators of the music that you play.
Keep in mind, the music you used may be owned or represented by multiple parties such as publishers, labels, or PROs. So, if your video is blocked, then it is possible that they found it offensive in some way.
You can upload the videos again (you might be having the copy) with a proper description with credits. If you don’t know how to learn from other Youtube creators or videos. Please mention that you don’t own the copyright of the music in the video and it is purely for entertainment purposes.
Give due credits to avoid getting your videos deleted out of nowhere. I understand that it can be really disheartening to start over again. But it happens, so be aware and try to educate yourself about YouTube marketing and creations.
I hope this answers your question. Good luck!
